Start by very gently browning the chopped garlic in fruity olive oil.
When the garlic is just beginning to brown, add some red pepper flakes and, almost immediately thereafter, a can of anchovy fillets.
Allow to cook gently over low heat, stirring from time to time, until the anchovies have almost entirely 'melted'. Add a pinch of salt (not too much, since the anchovies are already salty) and chopped parsley, stir and turn off the heat.
Meanwhile, cook your linguine (spaghetti are also excellent with this sauce) al dente in well salted water, drain (but not too well) and add to the skillet.
Mix well and allow the spaghetti to cook over gentle heat for just 30 seconds or so, long enough so that the pasta absorbs a bit of the sauce and any excess liquid evaporates. Taste for salt and serve immediately. Buon appetito!